1. Field of the Invention
The present invention generally relates to the manufacture of semiconductor devices and, more particularly, to an improved planarization technique for integrated circuit wafers which produces improved planarity in the wafers in a shorter polish time.
2. Background Description
As semiconductor devices become increasingly smaller, it is ever more important to achieve a planar surface for successful lithography at the smaller line dimensions. Chemical mechanical polishing (CMP) is fast becoming the planarization technique of choice. However, there are many problems to overcome such as dishing and nonuniformity.
Despite using various conditions of a single step CMP, planarization remains a critical issue. Combinations of reactive ion etching (RIE) with CMP have also been tried but still do not achieve the desired level of planarization. The combination of RIE and CMP is expensive and complex, requiring many steps and a mask. What is needed is a simpler, less expensive planarization process, preferably not requiring a mask and providing better control of the planarization process.